CN102958171B - By monitoring and binding hours lead to eliminate the method for the interference in time-division duplex radio network - Google Patents

Abstract

The present invention provides a method to cancel interference in a time division duplex wireless network. The method includes selecting a maximum timing advance for uplink transmission of a user equipment in a first wireless coverage area. The maximum timing advance is selected based on an uplink transmission performed by the user equipment or another user equipment in the first wireless coverage area and directed to at least one user equipment in a second wireless coverage area of the wireless network Potential interference between ongoing downlink transmissions. The basis for selecting the maximum timing advance may also include the coverage radius or other cell properties of the communication cells associated with the first and second wireless coverage areas. The maximum timing advance can be selected by the base station and transmitted to the user equipment.

Description

Method for eliminating interference in time division duplex wireless networks by monitoring and limiting timing advance

technical field

The present invention relates to wireless communication devices/systems, and more particularly to techniques for reducing interference in wireless time division duplex (TDD) networks.

Background technique

In a wireless communication system, TDD transmission uses the same frequency for downlink transmission and uplink transmission and allocates time slots (timeslot), so that downlink transmission and uplink transmission are scheduled to be performed at different times. A time slot is also called a time frame (frame). Frequency division duplex (FDD) uses different frequencies for downlink transmission and uplink transmission. When the data transmission rates of downlink transmission and uplink transmission are not equal or the frequency band is limited, time division duplexing is an ideal method. When the data transmission rates of downlink transmission and uplink transmission are equal, frequency division duplexing is a more efficient choice. Frequency division duplexing can also reduce interference by using different uplink and downlink frequencies.

When the time division duplex base station starts broadcasting information through the wireless channel, the base station uses the first time slot or the first sub-time frame (subframe) to transmit the information. The first sub-time frame is used for downlink transmission, followed by a guard period without any transmission. The subsequent second sub-time frame is used for uplink transmission between the user equipment and the base station. These sub-timeframes may be associated with uplink or downlink slots, but not a combination of uplink and downlink slots. Although uplink and downlink transmissions travel at the speed of light, there is still a measurable time difference between when a signal is transmitted and when it is received. This time difference is proportional to the distance between the base station and the user equipment.

Each communication cell (cell) is centered on a base station, and the timing of TDD is controlled by the base station. The user equipment is allowed to start the uplink transmission in advance within the aforementioned guard period, so that the uplink transmission can be completed within the receiving time slot of the base station. However, compared to the next data frame, the current transmitted data frame is too late or the transmission signal arrives too early may cause interference to adjacent communication cells or subsequent data frames, and may even be lost because they cannot be received by the base station. The wider the coverage radius of the communication cell (for example, up to 100 km), the more timing advance required by the UE. For example, when a communication cell with a smaller coverage radius is arranged next to another communication cell with a larger coverage radius, the uplink transmission in the large communication cell may occur at the same time as the downlink transmission in the small communication cell, thus Interference with communications in small communication cells.

Contents of the invention

In order to solve the above problems, the present invention proposes a technical solution for reducing interference in a wireless network.

In an embodiment according to the present invention, a user equipment is located in a first wireless coverage area of a wireless network using time division duplex transmission. When the user equipment selects a maximum timing advance for uplink transmission, according to the uplink transmission performed by the user equipment or another user equipment in the first wireless coverage area and a second wireless coverage area for the wireless network Potential interference between downlink transmissions performed by at least one of the user equipments. The maximum timing advance can be selected with reference to coverage radii or other cellular properties of the first and second wireless coverage areas. The first and second wireless coverage areas may be the same or different (covered by different base station or antenna configurations). The selection of the maximum timing advance may also refer to potential interference that may be caused by the UE itself.

The wireless network may adopt a time division long term evolution (timedivisionlongtermevolution, DT-LTE) communication scheme, and the selection of the maximum time advance may be at least one of the coverage radius of the first wireless coverage area and the coverage radius of the second wireless coverage area. Reference. Alternatively, the selection of the maximum timing advance may also be based on at least one of the special sub-time frame format used by the first wireless coverage area and the special sub-time frame format used by the second wireless coverage area.

The wireless network can adopt time division synchronous code division multiple access (timedivision-synchronous code division multiple access, TD-SCDMA) communication scheme, and the selection of the maximum time advance can also be based on the coverage radius of the first wireless coverage area and the coverage of the second wireless coverage area At least one of the radii is a reference. The UE can receive a message from the wireless network; the message includes maximum timing advance information. The base station serving the UE may broadcast a common maximum timing advance to all UEs in the first wireless coverage area, or transmit a dedicated maximum timing advance to each UE in the area. The selection of the maximum timing advance may also refer to the location of the user equipment in the first wireless coverage area. The base station may also regulate the maximum timing advance in the form of a numerical range.

In addition, when the timing advance currently used by the user equipment has reached or exceeded the maximum timing advance, the call of the user equipment can be interrupted. The base station in charge of the first wireless coverage area can detect whether the user equipment has reached the maximum timing advance, and take corresponding measures. For example, the base station can initiate a hand-over procedure, change the operating frequency, allocate the data of the user equipment to a sub-time frame not adjacent to the downlink-to-uplink transition point, interrupt the call by the base station, or The call is automatically disconnected by the user device that perceives that the maximum timing advance has been reached. After the call is disconnected due to the need to re-establish call capability for the user device, the user device may enter a no-service procedure. A temporary time limit may be set for the user equipment to prevent the user equipment from establishing a call through the base station covering the first wireless coverage area.

The base station responsible for the first wireless coverage area may receive a message including information indicating the radio properties of the second wireless coverage area. The base station can select the maximum timing advance according to the radio properties. In other embodiments, the user device detects the arrival time and/or received signal strength of the signals transmitted from the second wireless coverage area, and selects according to the arrival time and/or received strength of these signals Timing advance

The user equipment can also send the timing advance currently used by the user equipment to the base station in the form of a message. The base station can take appropriate measures according to the information to avoid interference caused by the UE.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1(A) and FIG. 1(B) are a schematic diagram and an example of a timing diagram of a TDD wireless communication system.

FIG. 2 illustrates an exemplary circuit of a wireless user equipment according to the present invention.

FIG. 3 illustrates an example circuit of a base station according to the present invention.

FIG. 4 is a flowchart of a timing advance limiting program of a user equipment according to the present invention.

FIG. 5 is a flow chart of a base station timing advance limiting program according to the present invention.

Description of main component symbols

100: wireless communication system 110, 140: base station

120, 150: user device 130: first wireless coverage area

160: Second wireless coverage area 170(1)-170(3): Sequence diagram

175: Reference time 180(1), 180(2): Protection period

190(1): Timing advance 190(2), 190(3): Interference period

210, 310: transmitter 220, 320: receiver

230, 330: controller 240, 340: memory

250(1)～250(M): Antenna 410～440, 510～550: Process steps

400: user device timing advance limit program

500: Base station timing advance limit program

Detailed ways

Please refer to the time division duplex (time division duplex, TDD) wireless communication system 100 shown in FIG. 1(A). The system 100 includes a first wireless coverage area 130 and a second wireless coverage area 160 . The first wireless coverage area 130 includes a base station (BS) 110 and a user equipment (UE) 120 , and the second wireless coverage area 160 includes a base station 140 and a user equipment 150 . User device 120 and user device 150 may be stationary or mobile devices. The base stations 110 and 140 can be connected to other wired data network facilities (not shown) and serve as a gateway or access point, so that the user equipment 120 and the user equipment 150 can be connected to these wired data network facilities.

The base stations 110 and 140 may include multiple antennas, and the user equipment 120 and the user equipment 150 may also include multiple antennas. The base stations 110 and 140 can individually communicate wirelessly with the user equipment 120 or the user equipment 150 using a broadband wireless communication protocol; the bandwidth of the broadband communication is much larger than the coherent bandwidth. For example, the broadband wireless communication protocol may be a time division-synchronous code division multiple access (TD-SCDMA) communication protocol or a time division long term evolution (TD-LTE) communication protocol.

A communication cell serving a specific UE may be referred to as a serving cell, and a communication cell located near the serving cell may be referred to as a neighbor cell. Taking the situation shown in FIG. 1(A) as an example, the first wireless coverage area 130 is the serving cell of the user equipment 120 , and the second wireless coverage area 160 is the serving cell of the user equipment 150 . Meanwhile, the first wireless coverage area 130 and the second wireless coverage area 160 are neighbor cells to each other.

The timing diagrams 170 ( 1 )- 170 ( 3 ) in FIG. 1(A) are shown relative to a reference time 175 as a reference; the reference time 175 marks the time point when uplink transmission starts for the base stations 110 , 140 . In this example, the timing diagram 170 ( 1 ) is used to roughly represent the operation timing of the base station 110 in the first wireless coverage area 130 . The timing diagram 170 ( 3 ) is used to schematically represent the operation timing of the base station 140 in the second wireless coverage area 160 . The sequence diagram 170( 2 ) is used to schematically represent the operation sequence of the user equipment 120 . There is a guard period (guard period) 180 (1) (or called a time interval (timinggap)) in the timing diagram 170 (1), and there is a guard period 180 (2) (or called a time interval) in the timing diagram 170 (3). interval). Since the coverage radius of the second wireless coverage area 160 is smaller than the coverage radius of the first wireless coverage area 130, the guard period 180(2) is shorter than the guard period 180(1). Similarly, counting from the reference time 175, the timing advance (timingadvance, TA) required for the uplink transmission to reach the base station 140 is relatively small. In order to minimize interference in the TDD system 100, the start time of the downlink transmission and the start time of the uplink transmission are synchronized by the base station, with the goal of having the same start time for both transmissions.

The transmission time from the base station 110 to the user equipment 120 or from the user equipment 120 to the base station 110 is denoted as T1. UE 120 compensates T1 with a timing advance 190(1). Since the signal arrives at the UE 120 with a delay of T1, the timing advance used by the UE 120 must be roughly twice T1. In the prior art, the base station will first specify an initial timing advance, and then adjust it. However, the message for adjusting the timing advance may be missed by the user device, or the user device cannot decode the message due to some errors. Therefore, the base station 110 generally cannot know the timing advance adopted by the user equipment 120 . When the base station 110 finds that the uplink transmission arrives too early or too late, the base station 110 will notify the user equipment 120 to gradually increase or decrease its timing advance until the receiving time of the uplink transmission matches the reference time 175 .

One of the problems with the timing advance 190(1) used by the user equipment 120 is that the start of the uplink transmission of the user equipment 120 is earlier than the guard period 180(2) of the second radio coverage area 160, during which the uplink transmission and downlink The times when transmissions overlap cause mutual interference, denoted as interference period 190(2). The larger the timing advance 190(1), the longer the disturbance period 190(2). The closer the UE 120 and UE 150 are, the greater the interference will be.

The interference period 190(2) is a problem for the UE 150, not only causing the loss of its transmission data, but also possibly affecting the cell searching/monitoring (CSM) performed by the UE 150 for the downlink transmission of neighboring cells. Cell search/monitoring is an important step for each UE when making mobility-related decisions such as cell handover. For example, in the cell search/monitoring procedure, the UE needs to acquire a considerable number of cell-specific reference signal (CSRS) symbols on the downlink channel.

The solution proposed by the present invention is to shorten the interference period by limiting the timing advance, such as the timing advance 190(1), within a known range, thereby improving the efficiency of the TDD system 100 . The amount of timing advance can be selected based on known properties of the time division duplex system 100 . For example, for TD-SCDMA and TD-LTE systems, the cell coverage radius is a known design limitation and can be used as a reference value for selecting the timing advance. In the TD-LTE system, a special sub-time frame (subframe) format can be used to limit the timing advance (details will be described later). Information in the TDD system 100 can be dynamically exchanged between devices and delivered to individual user devices. According to different system designs, the timing advance can be selected by the UE 120, the base station 110 or the TDD system 100, or jointly selected by the three.

FIG. 1(B) illustrates the system 100 after a period of time. At this time, the user equipment 150 has moved from the second wireless coverage area 160 to the first wireless coverage area 130 , and thus is no longer related to the second wireless coverage area 160 (marked by a dotted line). In this example, the timing advance 190(1) of the user equipment 120 has increased to the point where its uplink transmission causes interference to its own cell; 3) It is used to represent the problems caused by overlapping periods. Therefore, if the timing advance of the user equipment 120 is not limited, the interference may affect other user equipments (such as the user equipment 150 ) in the first wireless coverage area 130 . The method of limiting the timing advance will be summarized in FIG. 2 and FIG. 3 , and will be further described in detail in FIG. 4 and FIG. 5 .

It should be noted that FIG. 1(A) and FIG. 1(B) are simplified diagrams for illustrating the interference problem and potential solutions. Actually, the TDD system 100 may include more cells, base stations, UEs, and wired network facilities, such as routers, gateways, public switched telephone network (PSTN), internal connections, and so on. These devices can utilize existing communication protocols, such as Internet Protocol and Radio Resource Control (RRC) protocol, when exchanging messages. The aforementioned shapes and radii of the wireless coverage areas 130 and 160 are merely illustrative examples, and do not constitute limiting conditions of actual radio frequency coverage areas. For example, the shape of the coverage area may be oval or fan-shaped; the actual coverage area will be related to factors such as terrain, buildings, and engineering design.

It should also be noted that the scales in FIG. 1(A) and FIG. 1(B) are just examples, and are not drawn in true scale. These timing diagrams are for illustrative purposes only and may not be exact. For example, timing diagram 170(2) of user device 120 does not necessarily align with timing diagrams 170(1) and 170(3) in the manner shown.

Please refer to FIG. 2 . FIG. 2 is an example block diagram of a wireless communication device; the wireless communication device can be used as the user device 120 for executing a user device timing advance limiting procedure 400 to limit the interference period. The user device 120 includes a transmitter 210 , a receiver 220 and a controller 230 . The controller 230 is used to provide data to be transmitted by the transmitter 210 and to process signals received by the receiver 220 . In addition, the controller 230 is also responsible for other control functions related to transmission/reception. Part of the functions of the transmitter 210, the receiver 220 and the controller 230 can be realized by a modem; part of the functions of the transmitter 210 and the receiver 220 can be realized in the form of a wireless transceiver. It should be noted that these circuit blocks include analog-to-digital converters and digital-to-analog converters for converting signal formats.

The transmitter 210 may include a plurality of transmitting circuits for respectively providing the up-converted signals to the antennas 250(1)˜250(M) for transmission. The receiver 220 is responsible for receiving the signals detected by the antennas 250 ( 1 )˜ 250 (M), and transmitting the corresponding signals to the controller 230 . The receiver 220 may include a plurality of receiving circuits, each corresponding to an antenna. For ease of description, these transmitting circuits and receiving circuits are not shown one by one.

The controller 230 is a data processing device, such as a microprocessor or a microcontroller, which includes a memory 240 or other data storage blocks for storing data required by the controller 230 to execute various programs. The memory 240 can be built in the controller 230 or can be independent from the controller 230 . The program code for implementing the timing advance limiting program 400 of the user device can be stored in the memory 240 for the controller 230 to read. The restriction procedure 400 is used for selecting or determining the timing advance of providing the uplink transmission signal to the transmitter 210 .

The functions of the controller 230 can be realized by one or more coded logics in computer or processor-readable media (such as application-specific integrated circuits, digital signal processing instructions, software and other embedded logic). The memory 240 is used to store the operation data described here and/or software or processor instructions for realizing the operation. Therefore, the restriction program 400 can be implemented by using fixed logic circuits or programmable logic, for example, using a processor or a field programmable gate array to execute software or computer instructions.

FIG. 3 is an example block diagram of a wireless communication device; the wireless communication device can be used as the base station 110 for executing a base station timing advance limiting procedure 500 for limiting interference periods. The base station 110 includes a transmitter 310 , a receiver 320 , a controller 330 and a memory 340 . The functions of the transmitter 310, the receiver 320, the controller 330 and the memory 340 are similar to those of the circuit of the same name in FIG. 2 . The function of the limiting procedure 500 is also similar to the aforementioned limiting procedure 400, but is used to limit the timing advance of the base station.

FIG. 4 is a flowchart of a timing advance limiting program 400 of a UE. In step 410, the user equipment (such as user equipment 120) is directed to at least one user equipment in a second wireless coverage area of the wireless network according to the uplink transmission performed by itself or another user equipment in the first wireless coverage area. The potential interference between downlink transmissions performed by the user equipment 150 specifies a maximum timing advance for the uplink transmission of the user equipment 120 . The maximum timing advance may also be related to interference caused by any user device, including user device 120 . In step 420, the step of selecting the maximum timing advance is also based on a combination of at least one or more of the following factors: the coverage radius of the first wireless coverage area, the coverage radius of the second wireless coverage area, the coverage radius of the second wireless coverage area, A special sub-time frame format adopted by a wireless coverage area, and a special sub-time frame format adopted by a second wireless coverage area. Step 420 is an optional step (hence marked with a dotted box), and can be implemented together with step 410 .

In this example, the coverage radii of the first and second wireless coverage areas determine the respective required timing advances of the two areas. Therefore, the basis for selecting the timing advance of the user equipment 120 may be the coverage radius of the first wireless coverage area, the coverage radius of the second wireless coverage area (which may be larger or smaller than the former), or a combination of two radii, such as two The difference in radii or the difference in size between two regions. Alternatively, the timing advance may be selected based on information contained in a sub-time frame, such as a specific sub-time frame format used by the first or second wireless coverage area.

The concept of sub-timeframes is described further below. Certain timeframes contain special information. For example, after the first downlink sub-time frame is sent, the base station will send a downlink pilot (Pilot) time slot/channel message (commonly referred to as a DwPTS message). After the DwPTS message is a protection period, such as the protection periods 180(1), 180(2) in FIG. 1(A). After the guard period is an uplink pilot time slot/channel message (commonly known as an UpPTS message). The UE can use the guard period to calculate the maximum cell size of its serving cell and neighbor cells. In addition, the TD-LTE system allows eight special subframe formats (special subframe format, SSF). These Special Subtime Frame Formats (SSFs) specify the size of the DwPTS message, the length of the guard period, and the size of the UpPTS message. Therefore, the special sub-time frame format can be used as a reference for the user equipment to generate or determine a maximum timing advance to limit interference.

For the definition of the above-mentioned special sub-time frame format, please refer to Chapter 4.2 (3GPPTS36.211Chapter4.2) of the 3rd Generation Partnership Project Technical Document No. 36.211. The UE can obtain these special sub-time frame formats through a system information block (SIB)-1 sent by the base station. The base station can also use the (SIB)-1 message to convey the special sub-time frame format of the neighbor cell, or indicate whether the special sub-time frame format of the neighbor cell and the serving cell are the same. This formatting allows the user device to select/specify its timing advance or maximum timing advance, eg, using an algorithm or a lookup table.

In another example, a message received by the UE from the wireless network includes information indicating the maximum timing advance. The base station responsible for the first wireless coverage area may broadcast a common maximum timing advance to all UEs in the area. Alternatively, the base station in charge of the first wireless coverage area may transmit a dedicated maximum timing advance for each user equipment in the area. When selecting the maximum timing advance, the location of the user equipment in the first wireless coverage area may also be referred to. For example, when the user equipment roams in the first wireless coverage area 130, the neighboring cells of the user equipment may change, so that the maximum timing advance needs to be reselected.

The user equipment can also send the timing advance currently used by the user equipment to the base station in the form of a message. The base station can utilize the current timing advance to monitor and coordinate mobility handoffs of UEs in its coverage area. The message can be sent periodically, and the period can be fixed, or the message can be selected/notified by the base station. The message can also be sent when a specific event occurs. The event-triggered report message can be generated in the following situations: 1) when the timing advance has reached a value specified by the base station, 2) when the timing advance has reached the gap size corresponding to the minimum special sub-time frame format (across different configuration), or 3) when the timing advance has reached a value corresponding to the gap size of the special sub-time frame format of the serving cell. The variation of the cases 2) and 3) is to use a range instead of the value, that is, when the timing advance reaches the limit value minus a margin value, a report message is triggered. The report message can also be triggered by other conditions, not limited to the above ones. Chapter 5.1 of the 3rd Generation Partnership Project Technical Document No. 36.214 (3GPP TS36.214Chapter5.1) defines a reception-transmission time difference reported by the UE. The receive-transmit time difference can also be used to determine the timing advance currently used by the UE.

See Figure 4. In step 430, when the timing advance currently used by the user equipment has reached the maximum timing advance, the call of the user equipment may be interrupted. This interrupting step can be performed by the base station or the user equipment itself. Alternatively, the user equipment may notify the base station of the fact that the maximum timing advance has been reached, and the base station may take appropriate action. A preferred solution is to notify the user equipment to perform a handover (hand-over) procedure, and transfer to another cell to provide services, so as to continue to maintain its connection. When the base station determines that it is necessary to take the handover procedure, the base station can instruct the user equipment to handover to another cell, change the operating frequency, or distribute the data of the user equipment to the downlink-to-uplink conversion point (such as FIG. 1( Points in A) close to the interference region 190(2)) non-adjacent sub-timeframes. If the RRM procedure (such as the handover procedure) cannot be executed, the base station may stop interrupting the call of the UE. The base station can initiate these processing actions through an RRM command.

In step 440, the user device enters a no-service procedure after the call is disconnected due to the need to reestablish the call capability for the user device. The user equipment can use a random access channel (RACH) to re-establish a new call capability, thereby establishing a timing advance suitable for the new serving cell. The UE may wish to use the original serving cell to re-establish the call capability. Therefore, a waiting period or a temporary time limit can be set for the user device, so as to prevent the user device from re-establishing the call through the base station covering the first wireless coverage area before re-establishing the call, resulting in repeated interruption of the call.

In another example, the first wireless coverage area and the second wireless coverage area are adjacent to each other. The UE detects the arrival time and/or signal strength of the signal sent from the second wireless coverage area. For example, base stations in adjacent wireless coverage areas (such as base station 140 in coverage area 160) transmit signals, and the user equipment can determine the timing advance based on the arrival time and/or strength of the signals when they are received, or can Said to get location information. The location information of the user device can be obtained using the technology mentioned in the article "Evaluation of path-loss technologies for Location Services" in the 3rd Generation Partnership Project Technical Report No. 25.907. The UE can refer to its location information when deciding when to generate a timing advance report to the base station.

FIG. 5 is a flowchart of a base station timing advance limiting procedure 500 . In step 510, the base station (such as the base station 110) transmits uplink information to at least one user equipment (such as the user equipment 150 ) for potential interference between downlink transmissions performed, and select a maximum timing advance for uplink transmissions for the user equipment in the first wireless coverage area. In step 520, as previously mentioned, the selection of the maximum timing advance is also based on a combination of at least one or more of the following factors: the coverage radius of the first wireless coverage area, the coverage of the second wireless coverage area In the radius, a special sub-time frame format adopted by the first wireless coverage area, and a special sub-time frame format adopted by the second wireless coverage area. Step 520 is an optional step (hence marked with a dotted box), which can be implemented together with step 510 . As mentioned above, the selection of the maximum timing advance can be based on the location (eg geographic location) of the user equipment within the coverage of the base station. Alternatively, the selected maximum timing advance may also refer to cell-specific reference signal (CSRS) symbols. The base station can also specify the number of CSRS symbols used in cell search and monitoring (CSM).

In step 530, the maximum timing advance is transmitted to the UE. The user device can then set its own internal timing advance within the limits of the maximum timing advance. The base station can set a common maximum timing advance, a dedicated maximum timing advance, or establish a timing advance range. At some point, if the timing advance of the user equipment reaches the maximum timing advance, the user equipment will not be able to respond to the timing adjustment message (the message for increasing the timing advance of the user) sent by the base station. The user equipment can actively notify the base station that the maximum timing advance has been reached. In step 540, the base station in charge of the first wireless coverage area will check whether the user equipment has reached the maximum timing advance, for example, determine whether the user equipment no longer responds to the message to increase its timing advance, or whether it receives Information actively notified by the user device. In step 550, when the UE has reached the maximum timing advance, the base station initiates a hand-over procedure or terminates the call of the UE. As mentioned above, the base station may also take other corresponding measures.

The base station can further set a temporary time limit for the user equipment whose call is interrupted, so as to prevent the user equipment from attempting to re-establish the call. In addition, the base station may receive a message including information indicating the wireless properties of the second wireless coverage area. The base station can select the maximum timing advance according to the radio properties. The wireless property may include a cell coverage radius, a location of the UE in the second wireless coverage area, or a special sub-time frame format used in the second wireless coverage area.

In summary, the technology disclosed in the present invention is mainly applied to the user equipment located in the first wireless coverage area in the time division duplex wireless system, according to the user equipment itself or another user equipment in the first wireless coverage area A maximum timing advance is selected for the uplink transmission of the user equipment due to potential interference between the uplink transmission and the downlink transmission for at least one user equipment in a second wireless coverage area of the wireless network. The maximum timing advance can be selected with reference to coverage radii or other cellular properties of the first and second wireless coverage areas. The base station can select a maximum timing advance and transmit the maximum timing advance to the UE.

Through the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the claimed patent scope of the present invention.

Claims (25)

1. eliminate a method for the interference in a wireless network, this wireless network adopts time division duplex transmission, and the method comprises:

A user's set in one first wireless coverage area of this wireless network, potential interference between the uplink carried out according to another user's set in this user's set or this first wireless coverage area and the downlink transfer that at least one user's set in one second wireless coverage area of this wireless network is carried out, uplink for this user's set in this first wireless coverage area selected one maximum time lead, be limited in the Timing Advance of the uplink by this user's set in the scope of this lead maximum time.

2. the method for claim 1, it is characterized in that, this wireless network adopts time-division long-term evolution communication, and selected this maximum time lead contain one of radius and this second wireless coverage area with one of this first wireless coverage area and contain at least one in radius for reference frame.

3. the method for claim 1, it is characterized in that, this wireless network adopts time-division long-term evolution communication, and selected this maximum time the special sub-time frame format that uses with this first wireless coverage area of lead and the special sub-time frame format that uses of this second wireless coverage area at least one for reference frame.

4. the method for claim 1, it is characterized in that, this wireless network adopts a time division synchronous code division multiple access communication, and selected this maximum time lead contain one of radius and this second wireless coverage area with one of this first wireless coverage area and contain at least one in radius for reference frame.

5. the method for claim 1, is characterized in that, selected this maximum time lead comprise:

Receive a message, this message comprise instruction this first wireless coverage area in this user's set can use maximum time lead information.

6. method as claimed in claim 5, is characterized in that, multiple user's set is served by this first wireless coverage area, and the step receiving this message comprises:

Receive this message, this message comprises instruction this lead for the particular user device in this first wireless coverage area or for all user's sets in this first wireless coverage area maximum time.

7. the method for claim 1, is characterized in that, selected this maximum time lead comprise:

According to the position of this user's set in this first wireless coverage area, selected this maximum time lead.

8. the method for claim 1, is characterized in that, comprises further:

When this user's set in this first wireless coverage area has reached this lead maximum time, interrupt a call.

9. method as claimed in claim 8, is characterized in that, comprise further:

When call is because rebuilding delivery value and interrupting for this user's set, enter one without service routine.

10. method as claimed in claim 8, is characterized in that, comprise further:

For this user's set in this first wireless coverage area sets a temporary time restriction, set up a call to avoid this user's set through the base station containing this first wireless coverage area.

11. the method for claim 1, is characterized in that, this first wireless coverage area and this second wireless coverage area adjacent one another are, the method comprises further:

Detect at least one in arrival time of the signal sent from this second wireless coverage area and a signal strength signal intensity;

Wherein lead comprises with at least one in this arrival time and this signal strength signal intensity for reference frame selected this maximum time.

12. the method for claim 1, is characterized in that, comprise further:

This user's set in this first wireless coverage area transmits message to base station, this message comprises the information of the current Timing Advance that this user's set of instruction adopts, this message makes this base station that one can be taked suitably to take action, and causes interference to avoid this user's set in this first wireless coverage area.

13. the method for claim 1, is characterized in that, this first wireless coverage area is identical with this second wireless coverage area.

The method of the interference in 14. 1 kinds of elimination one wireless networks, this wireless network adopts time division duplex transmission, and the method comprises:

A base station in one first wireless coverage area of this wireless network, potential interference between the uplink carried out according to the user's set in this first wireless coverage area or another user's set and the downlink transfer that at least one user's set in one second wireless coverage area of this wireless network is carried out, uplink for this user's set in this first wireless coverage area selected one maximum time lead, be limited in the Timing Advance of the uplink by this user's set in the scope of this lead maximum time.

15. methods as claimed in claim 14, it is characterized in that, this wireless network adopts time-division long-term evolution communication, and selected this maximum time lead contain one of radius and this second wireless coverage area with one of this first wireless coverage area and contain at least one in radius for reference frame.

16. methods as claimed in claim 14, it is characterized in that, this wireless network adopts time-division long-term evolution communication, and selected this maximum time the special sub-time frame format that uses with this first wireless coverage area of lead and the special sub-time frame format that uses of this second wireless coverage area at least one for reference frame.

17. methods as claimed in claim 14, it is characterized in that, this wireless network adopts Time Division-Synchronous Code Division Multiple Access communication, and this maximum time lead also contain one of radius and this second wireless coverage area with one of this first wireless coverage area and contain at least one in radius for reference frame.

18. methods as claimed in claim 14, is characterized in that, multiple user's set is served by this first wireless coverage area, and the method comprises further:

This lead is broadcasted maximum time to the plurality of user's set in this first wireless coverage area.

19. methods as claimed in claim 14, it is characterized in that, multiple user's set is served by this first wireless coverage area, and selected this maximum time lead be included as the selected special time lead of a user's set in the plurality of user's set, the method comprises further:

Send this special time lead to this user's set.

20. methods as claimed in claim 14, is characterized in that, comprise further:

This base station receives a message, and this message comprises the information of the radio characteristics of this second wireless coverage area of instruction;

Wherein lead comprises with this wireless nature for reference frame selected this maximum time.

21. methods as claimed in claim 14, is characterized in that, selected this maximum time lead comprise:

Select this lead according to the position of this user's set in this first wireless coverage area maximum time.

22. methods as claimed in claim 14, is characterized in that, comprise further:

Whether this user's set detected in this first wireless coverage area has reached this lead maximum time; And

When a current Timing Advance of this user's set in this first wireless coverage area has reached this lead maximum time, perform a suitable action, to reduce this potential interference.

23. methods as claimed in claim 22, it is characterized in that, perform this suitable action and comprise at least one action performed in following action: initialization one handover procedure, change a frequency of operation, distributing user device data in the sub-time frame being not adjacent to one descending-uplink transfer point, and dropped calls.

24. methods as claimed in claim 22, is characterized in that, comprise further:

Be that this user's set in this first wireless coverage area sets a temporary time restriction during dropped calls, set up call to avoid this user's set through this base station containing this first wireless coverage area.

25. methods as claimed in claim 14, it is characterized in that, this first wireless coverage area is identical with this second wireless coverage area.